About Optics & Photonics TopicsOSA Publishing developed the Optics and Photonics Topics to help organize its diverse content more accurately by topic area. This topic browser contains over 2400 terms and is organized in a three-level hierarchy. Read more.

Topics can be refined further in the search results. The Topic facet will reveal the high-level topics associated with the articles returned in the search results.

The authors are with the Istituto Nazionale per la Fisica della Materia, National Institute for the Physics of Matter, and the Department of Physics, University of Genoa, Via Dodecaneso 33, 16146 Genoa, Italy.

Abstract

The effects of the refractive-index mismatch in confocal laser scanning microscopy were extensively studied. The axial aberration induced in the case of fluorescent microspheres was measured. The data were used to take into account the mismatch-induced aberrations and to consider object-size influence. Then we focused on the effect of refractive-index mismatch on the effective system’s point-spread function under different mismatch conditions and on depth of focusing. We experimentally verified that the peak of the point-spread function intensity profile decreases and the point-spread function itself progressively broadens as a function of the combined effect of the refractive-index mismatch and of the penetration depth, leading to a worsening of the system’s overall performances. We also performed these same measurements by embedding subresolution beads in an oocyte’s cytoplasm, which can be considered a turbid medium. We found evidence consistent with the previously developed theoretical model; in particular we found a strong dependence of the intensity peak on the focusing depth.

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Table 2

Percentage of Variation of the PSF Intensity Peak in Different Mismatch Conditions as a Function of the Focusing Deptha

a Percentage of variation of the PSF intensity peak with respect to the 0-µm focusing-depth intensity peak for the different media. The objective used is a 100× oil-immersed one.b Extrapolated from the experimental trend.

Tables (2)

Table 1

Lateral and Axial FWHMs as Functions of the Focusing Depth and the Immersion Medium’s Refractive Indexa

Depth (µm)

Air

Glycerol

Oil

Lateral (nm)

Axial (nm)

Lateral (nm)

Axial (nm)

Lateral (nm)

Axial (nm)

0

187 ± 8

484 ± 24

183 ± 14

495 ± 29

186 ± 6

489 ± 6

30

244 ± 10

623 ± 9

221 ± 5

545 ± 12

197 ± 10

497 ± 21

60

269 ± 11

798 ± 10

252 ± 7

628 ± 9

186 ± 12

496 ± 19

90

277 ± 5

1063 ± 24

268 ± 8

797 ± 26

191 ± 9

484 ± 12

a Lateral and axial FWHMs for PSF immersed in different media at different focusing depths. Standard error refers to an average over a set of 30–40 PSF. The objective used is a 100× oil-immersed one.

Table 2

Percentage of Variation of the PSF Intensity Peak in Different Mismatch Conditions as a Function of the Focusing Deptha

a Percentage of variation of the PSF intensity peak with respect to the 0-µm focusing-depth intensity peak for the different media. The objective used is a 100× oil-immersed one.b Extrapolated from the experimental trend.